[Research progress of intelligent responsive hydrogels in alveolar bone repair and regeneration]

Alveolar bone defects represent one of the most common complications following periapical diseases, periodontal pathologies, trauma, or tooth extraction. Conventional bone grafting techniques are constrained by limitations such as limited donor avaoil ability, immune rejection, and insufficient bioactivity. Smart responsive hydrogels, owing to their programmable physicochemical properties, capacity to construct biomimetic microenvironments, and spatiotemporally controllable drug/cell delivery capabilities, can effectively inhibit alveolar bone resorption and promote bone regeneration. Consequently, they offer comprehensive support for the repair and regeneration of both soft and hard periodontal tissues. This review systematically examines the design principles of multimodal responsive hydrogels (e.g., temperature-, pH-, enzyme-, and reactive oxygen species-responsive systems) and their mechanisms of microenvironmental regulation. This review further synthesizes recent advancements in their applications across critical biological processes, including osteogenic induction, angiogenesis, immunomodulation, and neuro-vascular-bone coupling. Additionally, the review delves into the current major challenges hindering clinical translation and provides insights into future research directions.